I have to agree with Kelly, with the exception that my SBEII doesn't kick like my older SBE did.
Are you using the gun for hunting, or clays?
For hunting purposes I believe inertia is really nice. They are simple and tough creatures that rarely, if ever, jam, gum up etc. I have witnessed inertia guns accidently going fully into the water on the river, and the guy field dried it in the boat, and it performed flawless for the morning hunt. As for the added recoil, I believe that during the excitement of the birds coming in, the actual felt recoil is minimal at that time due to the excitement of the situation.
My O/U's kick as much as my SBEII's when shooting trap loads. My oldest boy (16yo) loves to use his SBEII for trap, because he likes the weight and balance. So far, light trap loads have not been a problem with the gun.
Now before all the gas operated guys blast my reply - I own quite a few gas guns too, I just hate cleaning them all the time. But boy are they smooth, they are unbeatable for sporting clays and 200 round days.
If you are shooting the gun regularly for clays and hunting, go with a quality brand. If it is a couple times a year duck hunt - save the cash and buy a good lower priced model, and remember an O/U is the best all around shotgun to own - safe, simple, easy to clean, and adaptable.
My .02